Re: KASAN: use-after-free Read in adu_disconnect

[Johan Hovold]

On Fri, Sep 20, 2019 at 11:13:14AM +0200, Dmitry Vyukov wrote:
> On Fri, Sep 20, 2019 at 11:08 AM Johan Hovold <johan@xxxxxxxxxx> wrote:
> >
> > On Fri, Aug 09, 2019 at 01:24:04PM -0700, syzbot wrote:
> > > syzbot has found a reproducer for the following crash on:
> > >
> > > HEAD commit:    e96407b4 usb-fuzzer: main usb gadget fuzzer driver
> > > git tree:       https://github.com/google/kasan.git usb-fuzzer
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=13871a4a600000
> > > kernel config:  https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=0243cb250a51eeefb8cc
> > > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11c4c8e2600000
> > > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11d80d2c600000
> > >
> > > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > > Reported-by: syzbot+0243cb250a51eeefb8cc@xxxxxxxxxxxxxxxxxxxxxxxxx
> > >
> > > usb 1-1: USB disconnect, device number 4
> > > ==================================================================
> > > BUG: KASAN: use-after-free in atomic64_read
> > > include/asm-generic/atomic-instrumented.h:836 [inline]
> > > BUG: KASAN: use-after-free in atomic_long_read
> > > include/asm-generic/atomic-long.h:28 [inline]
> > > BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0x96/0x670
> > > kernel/locking/mutex.c:1211
> > > Read of size 8 at addr ffff8881d1d0aa00 by task kworker/0:1/12
> >
> > Let's resend and retest with commit id from latest report to make sure
> > the patch was actually applied during the last run:
> 
> The reply contains:
> patch:          https://syzkaller.appspot.com/x/patch.diff?x=1440268d600000
> that's what's being parsed and applied during testing.

Thanks for confirming, but I can't seem to find that link in the report
from syzbot:

	https://lkml.kernel.org/r/000000000000b05ce40592f8521a@xxxxxxxxxx

Is it supposed to be there?

Johan